latent prints

A latent print expert examines all types of fingerprints found at a crime scene, whether visable or not. The three categories of fingerprints include: latent, plastic, and contaminated. Latent fingerprints are the invisible prints made by the deposit of oils or perspiration from the friction ridges of one's fingers onto another substance. Plastic prints are those fingerprints impressed into easily malleable surfaces -- like plasticine or putty. Contaminated fingerprints are the result of material transfers, such as liquid blood, from the fingers to a surface.